UL 1277 THHN/THWN-2 Unscreened Control Cable 600V
UL 1277 THHN/THWN-2 Unscreened Control Cable is a 600V multicore tray/control cable using bare annealed copper conductors, PVC-FR / Nylon insulation and a black special-PVC outer sheath, without an overall metallic screen or drain wire. It is intended for industrial control circuits where tray-cable installation capability is required but electrostatic shielding is not.
PRODUCT OVERVIEW
This unscreened THHN/THWN-2 control cable is designed for industrial control and power-related circuits in trays, wireways, ducts and conduit. The source product data also lists direct burial, wet or dry locations, outdoor cable trays with sunlight-resistant rating, and Class 1, Division 2 hazardous-location applications.
The cable uses PVC-FR / Nylon insulated conductors, a nylon ripcord and a black special-PVC outer sheath. Unlike the screened version from the same product family, this construction has no aluminum-tape screen and no tinned-copper drain wire, reducing construction complexity and generally lowering finished diameter and cable weight.
KEY FEATURES
- UL 1277 referenced tray/control cable construction.
- 600V voltage rating and +90°C temperature rating.
- Bare annealed copper conductors.
- PVC-FR / Nylon insulation system.
- Unscreened construction: no aluminum-tape screen and no drain wire.
- Black special-PVC outer sheath.
- E2 core identification referenced to ICEA S-73-532.
- 10, 12 and 14 AWG listed range.
- 2-core flat and multicore round constructions up to 50 cores.
- Product data lists tray, wireway, duct, conduit, direct-burial, wet/dry and outdoor applications.
CABLE CONSTRUCTION
Conductor | Bare annealed copper |
Insulation | PVC-FR / Nylon (Polyvinyl Chloride – Flame Retardant / Nylon) |
Metallic Screen | None |
Drain Wire | None |
Ripcord | Nylon |
Outer Sheath | Special PVC (Polyvinyl Chloride) |
Sheath Colour | Black |
Core Identification | Color coded as E2 per ICEA S-73-532 |
SCREENED VS UNSCREENED THHN/THWN-2 CONTROL CABLE
Feature | Unscreened Type | Screened Type |
Metallic Screen | None | Aluminum tape |
Drain Wire | None | Tinned copper, 16 AWG, 7 strand |
Main Selection Reason | General control circuits where an overall metallic screen is not required | Control circuits where electrostatic interference needs to be reduced |
Construction | Simpler cable build | Additional screen and drain wire |
Overall Diameter / Weight | Generally slightly smaller and lighter | Generally slightly larger and heavier |
EMC / Interference Control | Depends on routing and system design; no overall metallic screen | Overall screen provides a dedicated electrostatic shielding layer |
Choose the unscreened version when the project does not require an overall metallic screen and cable routing is compatible with an unscreened control-cable design. Where the specification explicitly calls for shielding, or control circuits are routed near significant sources of electrical interference, the screened construction should be reviewed instead.
UL 1277 DESIGN & INSTALLATION FOCUS
Focus | How It Relates to This Product |
Complete Cable Assembly | Multicore copper conductors under an overall special-PVC jacket |
Tray / Raceway Use | Product data lists trays, wireways, ducts and conduit |
Outdoor Use | Product data lists aerial use with messenger support and outdoor tray use where sunlight resistance is required |
Wet / Dry Locations | Both are stated in the product application data |
Direct Burial | Stated as an approved application in the source product data; confirm marking on the supplied cable |
Hazardous Locations | Product data states Class 1, Division 2 use; project sealing and NEC requirements should be reviewed |
PRODUCT APPLICATIONS
- Class 1, Division 2 hazardous-location applications as stated in the product data, including oil, gas and petrochemical environments.
- Cable trays and wireways.
- Duct and conduit installations.
- Aerial installation when properly supported by a messenger.
- Direct-burial applications as stated in the product data.
- Wet or dry locations.
- Outdoor cable-tray installations where a sunlight-resistant rating is required.
The following data reproduces the listed unscreened product range. The 2-core construction is shown as a flat cable, while 3-core and higher constructions use round overall-diameter values.
| Cores | AWG | PVC Insul. mm | Nylon mm | Sheath mm | Overall Dia. mm | Weight kg/km | Nominal Ampacity A |
|---|---|---|---|---|---|---|---|
| 2 Flat | 10 | 0.51 | 0.10 | 1.14 | 6.37x10.58 | 166 | 40 |
| 2 Flat | 12 | 0.38 | 0.10 | 1.14 | 5.72x9.12 | 115 | 30.0 |
| 2 Flat | 14 | 0.38 | 0.10 | 1.14 | 5.21x8.00 | 86 | 40 |
| 3 | 10 | 0.51 | 0.10 | 1.14 | 11.37 | 237 | 30.0 |
| 3 | 12 | 0.38 | 0.10 | 1.14 | 9.56 | 156 | 25.0 |
| 3 | 14 | 0.38 | 0.10 | 1.14 | 8.52 | 114 | 25.0 |
| 4 | 10 | 0.51 | 0.10 | 1.14 | 12.45 | 298 | 32/40 |
| 4 | 12 | 0.38 | 0.10 | 1.14 | 10.36 | 188 | 24.0/30.0 |
| 4 | 14 | 0.38 | 0.10 | 1.14 | 9.25 | 135 | 20.0/25.0 |
| 5 | 10 | 0.51 | 0.10 | 1.14 | 14.41 | 391 | 32 |
| 5 | 12 | 0.38 | 0.10 | 1.14 | 11.39 | 247 | 24.0 |
| 5 | 14 | 0.38 | 0.10 | 1.14 | 10.09 | 174 | 20.0 |
| 6 | 10 | 0.51 | 0.10 | 1.14 | 15.67 | 482 | 32 |
| 6 | 12 | 0.38 | 0.10 | 1.14 | 12.40 | 292 | 24.0 |
| 6 | 14 | 0.38 | 0.10 | 1.14 | 10.95 | 204 | 20.0 |
| 7 | 10 | 0.51 | 0.10 | 1.14 | 15.67 | 515 | 28 |
| 7 | 12 | 0.38 | 0.10 | 1.14 | 12.40 | 320 | 21.0 |
| 7 | 14 | 0.38 | 0.10 | 1.14 | 10.95 | 226 | 17.5 |
| 8 | 10 | 0.51 | 0.10 | 1.14 | 16.97 | 591 | 28 |
| 8 | 12 | 0.38 | 0.10 | 1.14 | 14.20 | 377 | 21.0 |
| 8 | 14 | 0.38 | 0.10 | 1.14 | 11.84 | 260 | 17.5 |
| 9 | 10 | 0.51 | 0.10 | 1.14 | 18.31 | 672 | 28 |
| 9 | 12 | 0.38 | 0.10 | 1.52 | 15.27 | 440 | 21.0 |
| 9 | 14 | 0.38 | 0.10 | 1.14 | 12.76 | 290 | 17.5 |
| 10 | 10 | 0.51 | 0.10 | 1.52 | 19.57 | 726 | 20 |
| 10 | 12 | 0.38 | 0.10 | 1.52 | 16.28 | 488 | 21.0 |
| 10 | 14 | 0.38 | 0.10 | 1.52 | 14.38 | 345 | 12.5 |
| 11 | 10 | 0.51 | 0.10 | 1.52 | 19.86 | 789 | 20 |
| 11 | 12 | 0.38 | 0.10 | 1.52 | 16.51 | 531 | 15.0 |
| 11 | 14 | 0.38 | 0.10 | 1.52 | 14.58 | 372 | 12.5 |
| 12 | 10 | 0.51 | 0.10 | 1.52 | 20.49 | 852 | 20 |
| 12 | 12 | 0.38 | 0.10 | 1.52 | 17.02 | 560 | 15.0 |
| 12 | 14 | 0.38 | 0.10 | 1.52 | 15.01 | 396 | 12.5 |
| 13 | 10 | 0.51 | 0.10 | 2.03 | 21.88 | 961 | 20 |
| 13 | 12 | 0.38 | 0.10 | 1.52 | 17.31 | 616 | 15.0 |
| 13 | 14 | 0.38 | 0.10 | 1.52 | 15.27 | 427 | 12.5 |
| 14 | 10 | 0.51 | 0.10 | 2.03 | 22.60 | 1094 | 20 |
| 14 | 12 | 0.38 | 0.10 | 1.52 | 17.88 | 659 | 15.0 |
| 14 | 14 | 0.38 | 0.10 | 1.52 | 15.76 | 457 | 12.5 |
| 15 | 10 | 0.51 | 0.10 | 2.03 | 23.18 | 1161 | 20 |
| 15 | 12 | 0.38 | 0.10 | 1.52 | 18.35 | 700 | 15.0 |
| 15 | 14 | 0.38 | 0.10 | 1.52 | 16.16 | 485 | 12.5 |
| 16 | 10 | 0.51 | 0.10 | 2.03 | 23.81 | 1183 | 20 |
| 16 | 12 | 0.38 | 0.10 | 1.52 | 18.86 | 729 | 15.0 |
| 16 | 14 | 0.38 | 0.10 | 1.52 | 16.59 | 510 | 12.5 |
| 19 | 10 | 0.51 | 0.10 | 2.03 | 25.07 | 1360 | 20 |
| 19 | 12 | 0.38 | 0.10 | 1.52 | 19.86 | 853 | 15.0 |
| 19 | 14 | 0.38 | 0.10 | 1.52 | 17.45 | 589 | 12.5 |
| 20 | 10 | 0.51 | 0.10 | 2.03 | 25.82 | 1420 | 20 |
| 20 | 12 | 0.38 | 0.10 | 1.52 | 20.47 | 866 | 15.0 |
| 20 | 14 | 0.38 | 0.10 | 1.52 | 17.97 | 620 | 12.5 |
| 25 | 10 | 0.51 | 0.10 | 2.03 | 28.97 | 1753 | 18 |
| 25 | 12 | 0.38 | 0.10 | 2.03 | 24.00 | 1158 | 13.5 |
| 25 | 14 | 0.38 | 0.10 | 1.52 | 20.12 | 771 | 11.3 |
| 30 | 10 | 0.51 | 0.10 | 2.03 | 30.98 | 2075 | 18 |
| 30 | 12 | 0.38 | 0.10 | 2.03 | 25.61 | 1362 | 13.5 |
| 30 | 14 | 0.38 | 0.10 | 2.03 | 22.51 | 949 | 11.3 |
| 37 | 10 | 0.51 | 0.10 | 2.03 | 33.45 | 2520 | 16 |
| 37 | 12 | 0.38 | 0.10 | 2.03 | 27.58 | 1647 | 12.0 |
| 37 | 14 | 0.38 | 0.10 | 2.03 | 24.21 | 1152 | 10.0 |
| 40 | 10 | 0.51 | 0.10 | 2.03 | 34.75 | 2714 | 16 |
| 40 | 12 | 0.38 | 0.10 | 2.03 | 28.62 | 1810 | 12.0 |
| 40 | 14 | 0.38 | 0.10 | 2.03 | 25.10 | 1240 | 10.0 |
| 45 | 10 | 0.51 | 0.10 | 2.03 | 36.85 | 3036 | 14 |
| 45 | 12 | 0.38 | 0.10 | 2.03 | 30.3 | 2021 | 10.5 |
| 45 | 14 | 0.38 | 0.10 | 2.03 | 26.54 | 1381 | 8.8 |
| 50 | 10 | 0.51 | 0.10 | 2.03 | 38.27 | 3353 | 14 |
| 50 | 12 | 0.38 | 0.10 | 2.03 | 31.44 | 2228 | 10.5 |
| 50 | 14 | 0.38 | 0.10 | 2.03 | 27.51 | 1446 | 8.8 |
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From Production to Delivery
From raw material preparation to final shipmen, every stage is caretuly controled to ensure consistent conductor quality, reliable pertormance,and sae delivery. Our roduction,
inspection, packaging, and logistics processes are managed in accordance with applicable standards and project requirements.
Production
Annealed copper conductors are insulated with the specified PVC-FR / Nylon system, assembled into the required flat or multicore construction, fitted with the nylon ripcord and finished with the black special-PVC sheath.
Inspection
Inspection focuses on conductor condition, insulation and nylon-layer thickness, core identification, sheath integrity, finished dimensions, cable weight and electrical requirements defined for the approved construction.
Packaging
Finished cable is wound on suitable reels or drums according to cable size, weight and ordered length. Product identification can include standard reference, AWG size, core count, length and project reference.
Shipping
Before shipment, cable identification, packing and requested technical documents are checked against the order. Project-specific inspection records or approval documents should be confirmed before production.
Frequently Asked Questions
When should I choose the UL 1277 unscreened version instead of the screened version?
Choose the unscreened version when the project does not call for an overall metallic screen and the control circuit can be routed without dedicated cable shielding. It keeps the construction simpler and is generally slightly smaller and lighter than the corresponding screened type. If the circuit is sensitive to electrostatic interference or the specification explicitly requires shielding, use the screened construction instead.
Can this cable be used in cable trays and conduit?
Yes. The source product data specifically lists trays, wireways, ducts and conduit. UL 1277 is also the key tray-cable standard referenced for the complete multicore cable assembly. Cable size, fill, support and termination details should still be checked for the actual installation.
Can it be direct buried or used outdoors?
The product data states direct burial, wet or dry locations and outdoor cable-tray use where a sunlight-resistant rating is required. For procurement, those ratings should be confirmed on the offered cable marking, technical datasheet or approval documents rather than assumed from the product name alone.
What should be checked for Class 1, Division 2 applications?
The brochure lists Class 1, Division 2 hazardous-location use, including oil, gas and petrochemical environments. Hazardous-location projects also depend on fittings, seals, installation method and the governing electrical code. The cable marking and complete installation design should therefore be reviewed together.
Why does the 2-core cable have two dimensions instead of one diameter?
The 2-core construction is flat. Its size is therefore given as width × height, while 3-core and larger versions are listed with a nominal round overall diameter. This difference matters when selecting glands, conduit space and panel entries.
What products do you supply for the power cable industry?
We provide a wide range of cable materials and electrical products, including aluminum conductors, aluminum rods, aluminum wires, overhead conductors, medium and low voltage power cables, cable insulation materials, filling materials, shielding materials, and cable manufacturing consumables.We provide customized solutions according to different cable manufacturing requirements.
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